Method and apparatus for reduction of fracture of femur



May 13, 1941. F. A. LORENZO METHOD AND APPARATUS FOR REDUCTION OFFRACTURE OF FEMUR Filed June 15, 1940 Mala/d. A.LorelL w Faienied May13, 1941 warren stares rare EEQE TVEETHGD AND APPARATUS FQR REBUCTHGN FFRACTURE 0F FEMUR 4 Claims.

My invention relates to the reduction of bone fractures and moreparticularly to an improved method and apparatus for use in thereduction and immobilization of fracture of the neck of the femur.

The femur or thigh bone, it Will be recalled, is the longest bone in theskeleton and is formed at its upper end with a rounded head joined tothe shaft by a constricted neck, the base portion. of which liesadjacent two projections or eminences called the greater and lessertrochanters. The head articulates with the cavity in the hip bone calledthe acetabulum, and the lower end of the femur articulates with thetibia and the patella. Fractures of the femur usually occur in the neckor restricted portion between the rounded head and the area defined bythe trochanters, a large percentage of said fractures being in a planewhich is substantially transverse of the axis of the neck,

Heretofore, it has been suggested to reduce fractures of the abovementioned character, by means of a cast formed from plastic material orby mechanically fastening the bone elements to gether, in the vicinityof the fractured area, by means of wire, pin inserts or the like. Whilethe prior art arrangements no doubt function for their intendedpurposes, they are open to several objections, which are inherent,either in their construction or application and use.

The use of a cast, which incidentally was one of the earliest of theproposed methods of reduction, requires that the patient be practicallyenveloped within the plastic material, which not only causesconsiderable physical discomfort, but also in some instances results inserious consequences, due to the effect of induced temperatures upon therespiratory system. Wiring methods have not been satisfactory because oflimitation of space, the general inaccessibility of the fracture andmore particularly because of the necessity of providing a substantialsupport for the bone elements in the vicinity of the fracture. The useof pins or other metallic inserts has been suggested, however, theintroduction of these members into the desired supporting position iseffected by direct force, as by driving, which frequently results intrama and other undesirable after effects.

After considerable research and experimentation, I have developed animproved method and means for use in the reduction and immobilization offracture of the neck of the femur, whereby the above noted objections tothe prior art arrangements are overcome. In accordance With the presentinvention, the bone elements adjacent the fracture are supported andmaintained in the desired position by means of a threaded bolt member,constructed and arranged to function as an auxiliary core, interiorly ofthe neck of the femur, the threaded portion of the bolt having bearingengagement throughout a substantial area of the head and upper shaft inthe region of the trochanters, whereby considerable force may be exertedaxially of the neck of the femur to draw the parts together.

An object of my invention is to provide an improved method for thereduction of fracture of the neck of the femur.

- Another object of my invention is to provide an improved method ofreduction and immobilization of fracture of the neck of a femur.

Still another object of my invention is to provide improved meansadapted to be positioned interiorly of the neck of the femur andarranged to afford maximum support for the bone elements adjacent thefracture.

Yet another object of my invention is to provide improved meansinsertable through the neck of the femur and arranged so that a directforce can be exerted longitudinally of the axis of the neck, whereby theparts adjacent the fracture can be pulled together and maintained in thedee sired position.

A further object of my invention is to provide improved means forsupporting and maintaining the 'bone elements adjacent the fracture incorrect relative anatomical relationship prior to and during fixationthereof.

With these and other objects in View, which may be incident to myimprovements, the invention consists in the parts and combinations to behereinafter set forth and claimed, with the understanding that theseveral necessary elements, comprising my invention, may be varied inconstruction, proportions and arrangement, without departing from thespirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown inthe accompanying drawing means for carrying the same into practicaleffect, without limiting the improvements in their useful applicationsto the particular constructions, which for the purpose of explanation,have been made the subject of illustration.

In the drawing:

Figure 1 is a perspective View of a bolt, and guide members, the upperportion of the femur being shown in dotted outline.

Fig. .2 is an elevational view, partly in section, showing the positionof the bolt in the initial or starting position; and

Fig. 3is an elevational view, showing the bolt in the seated position.

Referring to the drawing and more particularly to Fig. 1, the improvedmeans adapted for use in the reduction and immobilization of fracture ofthe neck of a femur comprises, a bolt designated generally by numeral I,having a body portion formed with a head member 2 and a reduced taperedend portion 3. Between the head and tapered end, the body is formed witha threaded portion, the individual threads 4 being cut so that the edges5 thereof are comparatively thin and sharp. As will be seen in Fig. 2,the bolt I is also provided with a longitudinal opening or passage 5,adapted to receive a rigid element in the form of a pin 7, the purposeand function of which will be described more fully hereinafter.

The upper portion of the femur, as shown in Figs. 1 and 2 comprises arounded head 8, a restricted portion or neck 9, the base ll] of whichlies adjacent the greater and lesser trochanters H and i2 respectively,and a shaft I3, having a lower end adapted to articulate with the tibiaand patella. As heretofore pointed out, fractures of the femur usuallyoccur in the restricted portion 9, for example as at M, in a plane whichis substantially transverse of the axis of the neck. While the presentinvention is particularly adapted for use in connection with thefixation of fractures of the character disclosed, italso comprehendsreduction and immobilization of. fractures of the neck which occur inplanes at different angles to the axis of the neck.

When it is desired to reduce a fracture of the neck of a femur, inaccordance with the present invention, the bone elements adjacent afracture are positionedin correct anatomical relationship and .a passageis bored through the upper portion of shaft is, substantially centrallyof the neck 9, the passage terminating in the rounded head 8.. Pinmember 1, is then inserted into the passage thus bored and the elementsof the bone are, examined, as by X-ray, to determine whether or not theyare in thedesired position. If the inclination of the bore is found tobe in the proper direction relatively to the head and neck, a secondpassage substantially parallel to the first is bored through the uppershaft and neck, the second passage also terminating. in the roundedhead. A pin member 7 similar to pin 1, is then inserted in this passage,as shown in Fig. 2.

..After pins l-'! have been placed in seated position, the diameter ofthe passage which accommodates pin 1 is increased, as by reaming,usinga' reamer provided with an axial passage of sufficient diameter topermit pin 1 to pass freely through the reamer. It will thus be notedthat reaming is effected while pin 7 isin position, and that thispin'cooperates with pin 1' to inhibit or prevent rotative movement ofthe head with respect to the neck, during the reaming operation. Boltmember !,is thereafterwards introduced into the opening of the enlargedpassage, the end of pin l'exteriorly of, the shaft being inserted inpassage 6 forming axially of the bolt. Rotation of the bolt may beeffected by means of a suitable wrench or other tool adapted to engagewith the head member 2, the bolt being advanced so that the head thereofcontacts with the upper portion of the shaft I3. At this point, the end3' of the bolt as entered well into the compact bone area of the headand further rotation of the bolt causes the head to be drawn axially ofthe neck, whereby the bone elements adjacent the fracture M are forcedtightly together and maintained in fixed position. It will be noted thatduring the above described operation, pins 1 and 1' are seated in therespective passages and any rotative movement of the head 8 with respectto the neck is thus prevented. When the bolt is in the seated position,that is to say, after it has been turned down so that the parts aredrawn tightly together, pins I and 1 are removed.

By reasons of the design of threads 4, and more particularly due to thespacing, pitch and formation of crests which are thin and sharp,considerable force can be exerted axially of the neck of the femur topull the bone elements together,

since the threads have a considerable contact area throughout the bone.The material from which the bolt is made should, of course, be of anon-corrosive character because of. the environment in which it is used.In addition to being non corrosive, the material selected should beductible, free from oxidation and electrolysis, and have considerablestrength. A chromium-nickelmolybdenum steel, for example, 18% chromium,8% nickel and 2.3% molybdenum, is particularly adapted for use in makingthe bolts, since this material possesses all of the above mentioneddesirable required characteristics.

7 It willthus be appreciated that I have provided an improved method andmeans for reducing fractures of the neck of the femur, wherein the boneelements adjacent the fracture are temporarily supported and inhibitedagainst rotative movement prior to and during insertion ofthe means usedfor fixation of the fracture. The present invention also comprehends thenovel concept of using rigid elements in the form of. pins or the likefor preventing rotative movement of the bone elements, thexpins beingadapted to be withdrawn after fixation has been effected.

While I have shown and described the preferred embodiment of myinvention, I wish it to be understood that I do not confine myself tothe precise details of construction herein set forth, by way ofillustration, as it is apparent that many changes and variations may bemade therein, by those skilled in the art,-without departing from thespirit of the invention, or exceeding the scope of the appended claims.

What I claim is:

1. The method of reducing fracture of the neck of a femur comprisingpositioning the bone elements adjacent the fracture in correctanatomical relationship, boring a hole through the upper shaft portionaxially of the neck and terminating in the head portion, boring a secondhole through said bone elements substantially parallel to said firsthole, inserting into said holes rigid pin members, the pins cooperatingto prevent relative rotation of the head with respect to theneckincreasingthe diameter of the hole bored axially of the neck whilethe pin is seated therein, inserting a cannulated screw havingrelatively deep threads formed with thin sharp crests into the firsthole in telescopic relationship with the pin to afiix the head to theneck and thereafterwards withdraw-' ing said pins.

2. A lag screw for use in the reduction and immobilization of fractureof the femur comprising a body portion having a passage longitudinallythereof, said body being formed with a head memberand a reduced endportion, a plurality of. relatively deep threads formed in the bodybetween the head and end'portion the distance between threads being ofan inch, said threads having thin sharp crests.

3. A lag screw for use in the reduction and immobilization of fractureof the femur comprising a body portion having a passage longitudinallythereof, said body being formed with a substantially flat head memberand a tapered end portion, a plurality of relatively deep threads cut at8 threads per inch in the body between the head and tapered end, saidthreads having thin sharp crests.

4. The method of reducing fracture of the neck of a femur comprisingpositioning the bone elements adjacent the fracture in correctanatomical relationship, forming a passage through the upper shaftportion axially of. the neck and terminating in the head portion,forming a second passage through said bone elements substantiallyparallel to said first mentioned passage, inserting into said passagesrigid elements, the elements cooperating to prevent a relative rotationof the head with respect to the neck, increasing the diameter of thepassage formed axially of the neck while the rigid element is seatedtherein, inserting a cannulated screw having relatively deep threadsformed with thin sharp crests into the first passabe concentrictherewith and in telescopic relationship with the rigid element to afiixthe head to the neck and thereafterwards withdrawing said rigidelements.

FRANK A. LORENZO.

